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Hi, I'm wondering sth. about the projection of 3d objects. After the projection transformation, are these vertices of 3D objects projected to the near plane or the far plane ?

near plane.

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Ok then what is the purpose of the far plane?

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The perspective transformation (including the nonlinear divide by w) maps the frustum volume into the box volume [-1,1]x[-1,1]x[0,1] (Direct3D style).

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The far plane is part of the frustum description. Without it, your frustum would be unbounded. It is basically to clip geometry far away from the eye.

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So we are actually seeing the near plane on the screen right?

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perspective transform maps the view frustum

into a rectangle with depth

each point on the rectangle maps

to everything in world space

that could be behind that pixel

ie: something small close up

or something big along way away

imagine each pixel is a window into the 3D world

like a real window one meter wide

it can show something close up to one meter wide

but a mountain range could be 10 thousand meter's wide

both visible in the same window

the Z coordinate of each pixel represents how far
from the camera that vertex is

hope that helps

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Quote:
 Original post by skytigerperspective transform maps the view frustuminto a rectangle with deptheach point on the rectangle mapsto everything in world spacethat could be behind that pixelie: something small close upor something big along way awayimagine each pixel is a window into the 3D worldlike a real window one meter wideit can show something close up to one meter widebut a mountain range could be 10 thousand meter's wideboth visible in the same windowthe Z coordinate of each pixel represents how farfrom the camera that vertex ishope that helps

It helps, so this window is near-plane of the frustum, right?

yes.

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